BIOL 1543 Lecture Notes - Lecture 1: Edwin Hubble, Atomic Number, Unpaired Electron
19 May 2017
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Document Summary
Matter: anything with mass and that takes up space. Big bang theory: entire universe expanded from a tiny point, every distant object (galaxy) is receding from the earth quickly: discovered by edwin hubble. Organisms are composed of elements (compounds: matter is composed of chemical elements, elements can"t be broken down to other substances by ordinary chemical means, 92 elements in nature (few pure) Heavier elements came about through nuclear fusion: stars and supernova. Compound: substance consisting of 2 or more elements in a fixed ratio: more common than pure elements. 4 elements make up 96% of weight of living organisms: oxygen, carbon, hydrogen, nitrogen. Trace elements are essential in minute quantities. Each element has 1 type of atom. Atom: smallest unit of matter that still retains property of an element. Isotopes: have the same # of protons, different # of neutrons: behave identically in chemical reactions, radioactive isotopes: nucleus decays spontaneously, giving off particles and energy.
